The U.S. Navy submarine, Redfin, at the Philadelphia Navy Yard, in May, 1951, being converted into a radar picket boat.

View from above of the U.S. Navy Gato class submarine Redfin, at the Philadelphia Navy Yard, where it is being converted to a radar picket boat. Workers stand above the hull, which has been cut in half. Next, the two halves of the hull are seen being moved apart to facilitate addition of a 34 foot extension in the hull between the control room and the forward batteries. View of derricks and cranes around the Redfin and of Workers standing atop the boat's hull. Camera pans to closeup of one half of the boat as it is being winched away from the other, along a steel rail. View from below the bow. View from floor showing the two halves of the hull separated. Workers sketch diagram in chalk on floor of drydock. Scaffolding shown in place around the opening between the hull halves. Worker cutting steel plate with acetylene torch. A steel plate affixed to the hull, showing the name, USS Redfin (SSR-272) and the schedule for the project. The only item completed is the start date of May 1st. Workers engaged in fabricating the new section of hull.